U.S. patent number 5,417,569 [Application Number 08/211,444] was granted by the patent office on 1995-05-23 for multi-element dental implant.
Invention is credited to Jean Perisse.
United States Patent |
5,417,569 |
Perisse |
May 23, 1995 |
**Please see images for:
( Certificate of Correction ) ** |
Multi-element dental implant
Abstract
Suprastructure for a dental implant is provided with a false
stump defining a prosthesis base plate, a shank for anchoring the
false stump, with the shank including partially extending slots
forming surface segments capable of radial expansion, a hollow core
opening at a free end of the false stump and including a converging
ramp at the free end, a series of balls positioned in the hollow
core, with one of the balls abutting against the converging ramp so
as to be retained thereby and to exert a spacing pressure onto the
surface segments, and a screw abutting against a first ball of the
series of balls to cause the balls to be moved against the
converging ramp. The suprastructure can be used in combination with
a tubular implantal stump adapted to be anchored in the osseous
site and to accommodate the shank of the suprastructure.
Inventors: |
Perisse; Jean (Toulouse,
FR) |
Family
ID: |
9396545 |
Appl.
No.: |
08/211,444 |
Filed: |
April 26, 1994 |
PCT
Filed: |
October 09, 1991 |
PCT No.: |
PCT/FR91/00788 |
371
Date: |
April 26, 1994 |
102(e)
Date: |
April 26, 1994 |
PCT
Pub. No.: |
WO93/06787 |
PCT
Pub. Date: |
April 15, 1993 |
Current U.S.
Class: |
433/173; 433/174;
433/177 |
Current CPC
Class: |
A61C
8/0033 (20130101); A61C 8/005 (20130101); A61C
8/0065 (20130101); A61C 8/0054 (20130101); A61C
8/0069 (20130101) |
Current International
Class: |
A61C
8/00 (20060101); A61C 008/00 (); A61C 013/12 ();
A61C 013/225 () |
Field of
Search: |
;433/172,173,174,175,176,177 ;623/16,18,20,21,22,23 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
0114955 |
|
Aug 1984 |
|
EP |
|
0158333 |
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Oct 1985 |
|
EP |
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1961531 |
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Jul 1970 |
|
DE |
|
2305441 |
|
Aug 1974 |
|
DE |
|
3300764 |
|
Jul 1984 |
|
DE |
|
Other References
International Search Report and Annex in French and English. .
International Preliminary Examination Report in French..
|
Primary Examiner: Lucchesi; Nicholas D.
Attorney, Agent or Firm: Sandler, Greenblum &
Bernstein
Claims
I claim:
1. A suprastructure for a dental implant, comprising:
a false stump defining a prosthesis base plate and a shank; said
shank comprising a plurality of longitudinal slots defining a
plurality of surface segments capable of radial expansion; a hollow
core longitudinally extending in said false stump and said shank,
and comprising a converging ramp at an end of said shank and a
tapped portion at an end of said false stump; a series of balls
positioned within said hollow core between said converging ramp and
a screw, said screw positioned within said tapped portion.
2. The suprastructure according to claim 1, comprising a prosthesis
attached to said false stump.
3. The suprastructure according to claim 2, wherein said prosthesis
is attached to said false stump by bonding screwing or
clipping.
4. The suprastructure according to claim 1, wherein said screw
comprises a recess.
5. A suprastructure, comprising:
a false stump defining a prosthesis base plate;
a shank for anchoring said false stump, said shank comprising a
plurality of slots partially extending lengthwise from a free end
of said shank defining a plurality of surface segments capable of
radial expansion;
a longitudinally extending hollow core in said suprastructure
opening at a free end of said false stump and comprising a
converging ramp at said free end of said shank;
a series of balls in mutual contact positioned in said hollow core,
one of said series of balls abutting against said converging ramp
so as to be retained thereby and to exert a spacing pressure onto
said plurality of surface segments; and
an element positioned in said hollow core in a vicinity of said
free end of said false stump abutting against a first ball of said
series of balls to cause said series of balls to be moved into
position with said one ball against said converging ramp.
6. The suprastructure according to claim 5, wherein said element
comprises a screw positioned within a tapped portion of said hollow
core.
7. The suprastructure according to claim 6, wherein said screw
comprises a recess.
8. The suprastructure according to claim 6, wherein said converging
ramp comprises a truncated ramp having an apex angle of between
45.degree. and 75.degree..
9. The suprastructure according to claim 8, wherein said converging
ramp comprises a truncated ramp having an apex angle of about
60.degree..
10. Multi-element dental implant for further grafting and anchoring
of a prosthesis onto an osseous site, comprising:
(a) a suprastructure comprising:
(i) a false stump defining a prosthesis base plate,
(ii) a shank for anchoring said false stump, said shank comprising
a plurality of slots partially extending lengthwise from a free end
of said shank defining a plurality of surface segments capable of
radial expansion,
(iii) a longitudinally extending hollow core in said suprastructure
opening at a free end of said false stump and comprising a
converging ramp at said free end of said shank,
(iv) a plurality of balls serially positioned in said hollow core,
each of said plurality of balls being in contact with another of
said plurality of balls, one of said plurality of balls abutting
against said converging ramp so as to be retained thereby and to
exert a spacing pressure onto said plurality of surface segments,
and
(v) a screw positioned within a tapped portion of said hollow core
in a vicinity of said free end of said false stump, said screw
abutting against a first ball of the series of said plurality of
balls to cause said series of balls to be moved into position;
and
(b) a tubular implantal stump adapted to be anchored in the osseous
site and to accommodate said shank.
11. The dental implant according to claim 10, wherein said
converging ramp comprises a truncated ramp having an apex angle of
between 45.degree. and 75.degree..
12. The dental implant according to claim 11, wherein said shank
and said false sump have collinear axes.
13. The dental implant according to claim 11, wherein said shank
and said false stump have axes defining a predetermined angle
therebetween.
14. The dental implant according to claim 11, wherein said screw
includes a recess.
15. The dental implant according to claim 10, wherein said
converging ramp comprises a truncated ramp having an apex angle of
about 60.degree..
16. The dental implant according to claim 15, wherein said shank
and said false stump have collinear axes.
17. The dental implant according to claim 15, wherein said shank
and said false stump have axes defining a predetermined angle
therebetween.
18. The dental implant according to claim 10, wherein said shank
and said false stump have collinear axes.
19. The dental implant according to claim 10, wherein said shank
and said false stump have axes defining a predetermined angle
therebetween.
20. The dental implant according to claim 10, wherein said screw
includes a recess.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a multi-element dental implant for
further grafting and anchoring of a dental prosthesis onto an
osseous site. The invention includes the component parts of this
implant as well as implant dentures made therefrom.
2. Discussion of Background Information
Dental implantology shows an increasing tendency leading to the use
of multi-element implants that are composed of two separate
elements, with the grafting thereof being successively effected.
These multi-element implants are provided with an implantal stump
composed of a tubular element which is anchored in the osseous
site, and a suprastructure composed of an anchoring shank formed on
the implantal stump and of a false stump that serves as a
prosthesis base plate. Further, in implants such as the so-called
normal implants, the false stump and the anchoring shank have
collinear axes; whereas, in implants such as the so-called
preangulated implants, the axes form an angle up to 20.degree..
First, the implant stump is anchored by screwing or any other way
(DE 1,961,531, EP 0,114,955, or U.S. Pat. No. 3,708,883) in the
osseous site, then the suprastructure is attached to the implantal
stump by means of the anchoring shank so as to cause the false
stump to take a suitable position. Actually, such anchoring in the
implantal stump of the shank is achieved by two methods.
In one method the suprastructure shank is composed of a smooth bar,
and is permanently sealed within the tubular implantal stump by
using a cement. However, in this method, should clinical problems
arise, then no removal of the suprastructure will not be
possible.
In the other known anchoring method, the suprastructure shank is
screwed into the implantal stump through conjugate threading and
tapping as provided on these elements (See U.S. Pat. No.
3,589,011). In this method the suprastructure is releasable.
However, positioning is inaccurate and hazardous, so much in the
longitudinal direction (along the implant axis), because a
determination, upon screwing, of the tightening stop limit proves
difficult and relates to the orientation of the suprastructure
about its axis, which is conditioned upon the final thread
position. This angular inaccuracy forms a serious defect impairing
preangulated implants, so that suitable positioning can hardly be
made using this anchoring method.
SUMMARY OF THE INVENTION
The present invention intends to provide an improved multi-element
implant, exempt from the above-mentioned defects. The invention
aims at achieving accurate anchoring in the implantal stump (deep
along the longitudinal axis and angularly about such axis) of the
suprastructure while maintaining easy removal, if necessary.
Accordingly, the multi-element dental implant involved in the
invention is of the type comprising a suprastructure provided with
a false stump used as a prosthesis base plate and a shank for
anchoring thereof, and a tubular implantal stump adapted to be
anchored in the osseous site and to accommodate the suprastructure
shank. In accordance with the present invention, the implant is
characterized in that:
The suprastructure comprises a hollow core extending lengthwise
therein, the hollow core opening at the free end of the false stump
and being provided at the free end of the shank with a converging
ramp,
the suprastructure shank comprises a number of slots extending
partially lengthwise therein from its free end so as to define
several surface areas able to withstand radial expansion,
several balls are accommodated within the suprastructure hollow
core as a series maintaining the balls in mutual contact, the
latter thereof abutting against a cone-shaped ramp of the shank so
as to be retained thereby, and to exert onto surface areas of the
shank a spacing pressure,
a screw is screwed within a tapped portion of the hollow core in
the vicinity of the free end of the false stump, the screw abutting
against the first ball so as to cause the series of balls to be
moved and fixed.
Hence, in the implant of the invention, the tubular implantal stump
which is of a type known per se, is anchored in the osseous site
conventionally, such as by screwing or any other way already known.
The suprastructure is anchored in this implantal stump by inserting
its anchoring shank therein and positioning it suitably, angularly
and along the longitudinal axis. Then, a mere actuation of the
upper screw will suffice to entail both the shank expansion and
setting thereof inside the implantal stump. Such an operation does
not modify the suprastructure angular axial position which results
in the suprastructure being accurately set into a selected
position. Removal of the suprastructure is achieved by simply
actuating the screw counterclockwise, whereby the anchoring shank
is released in the radial direction, and can be extracted.
The implant in accordance with the invention can be of the normal
type, such as the shank and false stump of the suprastructure
having collinear axes. Also, the implant can be preangulated so
that the axes of the shank and false stump form a predetermined
angle, e.g., 6.degree., 12.degree. or 20.degree..
The invention also relates to a suprastructure as above defined for
dental implant, characterized in that it comprises a hollow
anchoring shank provided with a number of longitudinal slots
defining several surface areas able to withstand radial expansion
and the suprastructure is provided with a hollow core which is
bored longitudinally therein, and comprises, at the end of the
shank, a converging ramp, and, at the end of the false stump, a
tapped portion. A series of balls is positioned within the hollow
core between the converging ramp and a screw that is screwed into
the tapped portion.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features, objects and advantages of the invention will be
apparent from the description as follows refering to the appended
drawings, which represent two examplary embodiments, that form part
of the present description:
FIGS. 1 and 2 are axial cross-sections at expanded scale showing a
preangulated implant in accordance with the invention,
suprastructure and implantal stump thereof, respectively,
FIG. 3 is a transversal cross-section of the suprastructure through
a plane AA,
FIG. 4 is a schematic cross-section showing both the implant and
prosthesis thereof as positioned on the site,
FIG. 5 is a schematic cross-section of another embodiment (normal
implant) ready to accommodate a clipped prosthesis.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The multi-element dental implant shown for example at FIGS. 1-4
(scale approximatively 8) is a preangulated implant whereof the
angle is equal to 12.degree.. It is composed of an implantal stump
1 (FIG. 2) made for example of titanium, which takes a tubular form
inclusive of a cylindrical hollow core 1a that is closed by a
hemispherical bottom plate 1b. On its outer cylindrical face, this
element is provided with a threading 2 to permit conventional
anchoring thereof in the maxillary site.
Further, the other implant element, the so-called suprastructure 3
(FIG. 1), is also made of titanium and comprises a false stump 4,
shank 5 and a gingival junction 6 formed therebetween. The false
stump longitudinal axis X forms together with the shank
longitudinal axis Y a 12.degree. angle. Moreover, shoulders such as
6a and 6b define the gingival junction 6. These are expected to
correspond with the bone/gum interface and the gum outer surface,
respectively, as shown in FIG. 4.
In the suprastructure 3 is bored in either part lengthwise
longitudinal axis X, Y thereof a hollow core 7 with circular
cross-section. At the free end of the shank 5, this hollow core 7
comprises a truncated ramp 8 having an apex angle thereof which is
in particular, within 45.degree. and 75.degree.more preferably
about 60.degree.. Additionally, the hollow core 7 is tapped to part
of the length 9 thereof at the free end of its false stump.
The suprastructure shank 5 shows an outer diameter which is
slightly inferior to the bore of the implantal stump 2 so as to get
accommodated therein with smooth Friction. The suprastructure is
divided partially lengthwise into several segments such as 5a by a
number of longitudinal slots 13 (herein in the number of four)
starting from the shank free end. Thus, the this shank can
withstand a radial expansion in view of the resilient free motion
of the segment 5a.
The hollow core 7 of the suprastructure is herein provided with
several balls such as 11a, 11b formed in a series in mutual contact
between the cone shaped ramp 8 and a screw 10 screwed in the tapped
portion 9. These balls are given a diameter slightly smaller than
that of the hollow core 7 so as to be able to move therein in the
longitudinal direction. Moreover, the last ball 11a, the so-called
expansion ball, comes into contact with the cone shaped ramp 8,
whereas the other balls such as 11b transfer the longitudinal
motion of the screw 10 thereto, the first ball of the series having
contact therewith.
The screw 10 comprises a recess 10a whereby handling thereof can be
made with a sharped-nosed key. Hence, the practitioner can generate
a longitudinal displacement of the ball series that causes the
expansion ball 11a to engage in the cone shaped ramp 8, and,
consequently, cause spacing pressure to be applied onto the
segments 5a. Further, the practitioner can release the same
segments by performing a reversal of the operative steps.
FIG. 4 shows the implant as grafted to site with prosthesis 12
thereof. The practitioner anchors the implantal stump 1 within the
osseous site of the maxillary conventionally. Thereafter, he
introduces the suprastructure shank 5 in the implantal stump.
Further, he axially and angularly positions the shank to bring the
false stump 4 into ideal position and orientation and then he so
acts on the screw 10 as to position the shank 5 in its expanded
condition and set it in the implantal stump. The suprastructure can
be removed, as needed, by operating the screw through a reverse
operating sequence to release the shank segments.
Moreover, the prosthesis 12 is secured to the false stump 4 by any
known means. In the example shown, this prosthesis is made of
ceramics and comprises an internal metal cover 12a which is bonded
to the false stump. Of course, the false stump of the implant can,
in accordance with the invention, be adapted to provide use of any
other type of prosthesis, anchoring, e.g., anchoring by means of
screwing (on behalf of conjugated threading and tapping as formed
onto the false stump and the prosthesis or by clipping as shown by
FIG. 5).
This FIG. 5 applies to the case of a normal implant (common axis Z
shared by the shank and the false stump), whereof the false stump
is equipped with the clipping head.
It should be noted that the anchored prosthesis may, upon the
circumstances be provided with a channel having dimensions larger
than the recess 10a of the screw to access thereat and act thereon
upon the prosthesis anchoring. The prosthesis so anchored is of the
fixed type although the practitioner can readily remove it at any
time. The channel providing access to the screw 10 can be closed by
any means to be extracted by the practitioner when required.
* * * * *